/* * This file is part of the MicroPython project, http://micropython.org/ * * The MIT License (MIT) * * Copyright (c) 2016 Scott Shawcroft * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ // This file contains all of the Python API definitions for the // bitbangio.I2C class. #include "shared-bindings/bitbangio/I2C.h" #include "shared-bindings/microcontroller/Pin.h" #include "shared-bindings/util.h" #include "lib/utils/buffer_helper.h" #include "lib/utils/context_manager_helpers.h" #include "py/mperrno.h" #include "py/runtime.h" //| .. currentmodule:: bitbangio //| //| :class:`I2C` --- Two wire serial protocol //| ------------------------------------------ //| //| .. class:: I2C(scl, sda, \*, frequency=400000) //| //| I2C is a two-wire protocol for communicating between devices. At the //| physical level it consists of 2 wires: SCL and SDA, the clock and data //| lines respectively. //| //| :param ~microcontroller.Pin scl: The clock pin //| :param ~microcontroller.Pin sda: The data pin //| :param int frequency: The clock frequency of the bus //| STATIC mp_obj_t bitbangio_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *pos_args) { mp_arg_check_num(n_args, n_kw, 0, MP_OBJ_FUN_ARGS_MAX, true); bitbangio_i2c_obj_t *self = m_new_obj(bitbangio_i2c_obj_t); raise_error_if_deinited(shared_module_bitbangio_i2c_deinited(self)); self->base.type = &bitbangio_i2c_type; mp_map_t kw_args; mp_map_init_fixed_table(&kw_args, n_kw, pos_args + n_args); enum { ARG_scl, ARG_sda, ARG_frequency }; static const mp_arg_t allowed_args[] = { { MP_QSTR_scl, MP_ARG_REQUIRED | MP_ARG_OBJ }, { MP_QSTR_sda, MP_ARG_REQUIRED | MP_ARG_OBJ }, { MP_QSTR_frequency, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 400000} }, }; mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)]; mp_arg_parse_all(n_args, pos_args, &kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args); assert_pin(args[ARG_scl].u_obj, false); assert_pin(args[ARG_sda].u_obj, false); const mcu_pin_obj_t* scl = MP_OBJ_TO_PTR(args[ARG_scl].u_obj); const mcu_pin_obj_t* sda = MP_OBJ_TO_PTR(args[ARG_sda].u_obj); shared_module_bitbangio_i2c_construct(self, scl, sda, args[ARG_frequency].u_int); return (mp_obj_t)self; } //| .. method:: I2C.deinit() //| //| Releases control of the underlying hardware so other classes can use it. //| STATIC mp_obj_t bitbangio_i2c_obj_deinit(mp_obj_t self_in) { bitbangio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); shared_module_bitbangio_i2c_deinit(self); return mp_const_none; } MP_DEFINE_CONST_FUN_OBJ_1(bitbangio_i2c_deinit_obj, bitbangio_i2c_obj_deinit); //| .. method:: I2C.__enter__() //| //| No-op used in Context Managers. //| // Provided by context manager helper. //| .. method:: I2C.__exit__() //| //| Automatically deinitializes the hardware on context exit. See //| :ref:`lifetime-and-contextmanagers` for more info. //| STATIC mp_obj_t bitbangio_i2c_obj___exit__(size_t n_args, const mp_obj_t *args) { (void)n_args; shared_module_bitbangio_i2c_deinit(args[0]); return mp_const_none; } STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(bitbangio_i2c_obj___exit___obj, 4, 4, bitbangio_i2c_obj___exit__); static void check_lock(bitbangio_i2c_obj_t *self) { if (!shared_module_bitbangio_i2c_has_lock(self)) { mp_raise_RuntimeError("Function requires lock"); } } //| .. method:: I2C.scan() //| //| Scan all I2C addresses between 0x08 and 0x77 inclusive and return a list of //| those that respond. A device responds if it pulls the SDA line low after //| its address (including a read bit) is sent on the bus. //| STATIC mp_obj_t bitbangio_i2c_scan(mp_obj_t self_in) { bitbangio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); raise_error_if_deinited(shared_module_bitbangio_i2c_deinited(self)); check_lock(self); mp_obj_t list = mp_obj_new_list(0, NULL); // 7-bit addresses 0b0000xxx and 0b1111xxx are reserved for (int addr = 0x08; addr < 0x78; ++addr) { bool success = shared_module_bitbangio_i2c_probe(self, addr); if (success) { mp_obj_list_append(list, MP_OBJ_NEW_SMALL_INT(addr)); } } return list; } MP_DEFINE_CONST_FUN_OBJ_1(bitbangio_i2c_scan_obj, bitbangio_i2c_scan); //| .. method:: I2C.try_lock() //| //| Attempts to grab the I2C lock. Returns True on success. //| STATIC mp_obj_t bitbangio_i2c_obj_try_lock(mp_obj_t self_in) { bitbangio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); raise_error_if_deinited(shared_module_bitbangio_i2c_deinited(self)); return mp_obj_new_bool(shared_module_bitbangio_i2c_try_lock(self)); } MP_DEFINE_CONST_FUN_OBJ_1(bitbangio_i2c_try_lock_obj, bitbangio_i2c_obj_try_lock); //| .. method:: I2C.unlock() //| //| Releases the I2C lock. //| STATIC mp_obj_t bitbangio_i2c_obj_unlock(mp_obj_t self_in) { bitbangio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); raise_error_if_deinited(shared_module_bitbangio_i2c_deinited(self)); shared_module_bitbangio_i2c_unlock(self); return mp_const_none; } MP_DEFINE_CONST_FUN_OBJ_1(bitbangio_i2c_unlock_obj, bitbangio_i2c_obj_unlock); //| .. method:: I2C.readfrom_into(address, buffer, \*, start=0, end=len(buffer)) //| //| Read into ``buffer`` from the slave specified by ``address``. //| The number of bytes read will be the length of ``buffer``. //| //| If ``start`` or ``end`` is provided, then the buffer will be sliced //| as if ``buffer[start:end]``. This will not cause an allocation like //| ``buf[start:end]`` will so it saves memory. //| //| :param int address: 7-bit device address //| :param bytearray buffer: buffer to write into //| :param int start: Index to start writing at //| :param int end: Index to write up to but not include //| STATIC mp_obj_t bitbangio_i2c_readfrom_into(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { enum { ARG_address, ARG_buffer, ARG_start, ARG_end }; static const mp_arg_t allowed_args[] = { { MP_QSTR_address, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} }, { MP_QSTR_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, { MP_QSTR_start, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} }, { MP_QSTR_end, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} }, }; bitbangio_i2c_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]); raise_error_if_deinited(shared_module_bitbangio_i2c_deinited(self)); mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)]; mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args); check_lock(self); mp_buffer_info_t bufinfo; mp_get_buffer_raise(args[ARG_buffer].u_obj, &bufinfo, MP_BUFFER_WRITE); int32_t start = args[ARG_start].u_int; uint32_t length = bufinfo.len; normalize_buffer_bounds(&start, args[ARG_end].u_int, &length); uint8_t status = shared_module_bitbangio_i2c_read(self, args[ARG_address].u_int, ((uint8_t*)bufinfo.buf) + start, length); if (status != 0) { mp_raise_OSError(status); } return mp_const_none; } MP_DEFINE_CONST_FUN_OBJ_KW(bitbangio_i2c_readfrom_into_obj, 3, bitbangio_i2c_readfrom_into); //| .. method:: I2C.writeto(address, buffer, \*, start=0, end=len(buffer), stop=True) //| //| Write the bytes from ``buffer`` to the slave specified by ``address``. //| Transmits a stop bit if ``stop`` is set. //| //| If ``start`` or ``end`` is provided, then the buffer will be sliced //| as if ``buffer[start:end]``. This will not cause an allocation like //| ``buffer[start:end]`` will so it saves memory. //| //| :param int address: 7-bit device address //| :param bytearray buffer: buffer containing the bytes to write //| :param int start: Index to start writing from //| :param int end: Index to read up to but not include //| :param bool stop: If true, output an I2C stop condition after the //| buffer is written //| STATIC mp_obj_t bitbangio_i2c_writeto(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { enum { ARG_address, ARG_buffer, ARG_start, ARG_end, ARG_stop }; static const mp_arg_t allowed_args[] = { { MP_QSTR_address, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} }, { MP_QSTR_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, { MP_QSTR_start, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} }, { MP_QSTR_end, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} }, { MP_QSTR_stop, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = true} }, }; bitbangio_i2c_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]); raise_error_if_deinited(shared_module_bitbangio_i2c_deinited(self)); check_lock(self); mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)]; mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args); // get the buffer to write the data from mp_buffer_info_t bufinfo; mp_get_buffer_raise(args[ARG_buffer].u_obj, &bufinfo, MP_BUFFER_READ); int32_t start = args[ARG_start].u_int; uint32_t length = bufinfo.len; normalize_buffer_bounds(&start, args[ARG_end].u_int, &length); // do the transfer uint8_t status = shared_module_bitbangio_i2c_write(self, args[ARG_address].u_int, ((uint8_t*) bufinfo.buf) + start, length, args[ARG_stop].u_bool); if (status != 0) { mp_raise_OSError(status); } return mp_const_none; } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(bitbangio_i2c_writeto_obj, 1, bitbangio_i2c_writeto); STATIC const mp_rom_map_elem_t bitbangio_i2c_locals_dict_table[] = { { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&bitbangio_i2c_deinit_obj) }, { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) }, { MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&bitbangio_i2c_obj___exit___obj) }, { MP_ROM_QSTR(MP_QSTR_scan), MP_ROM_PTR(&bitbangio_i2c_scan_obj) }, { MP_ROM_QSTR(MP_QSTR_try_lock), MP_ROM_PTR(&bitbangio_i2c_try_lock_obj) }, { MP_ROM_QSTR(MP_QSTR_unlock), MP_ROM_PTR(&bitbangio_i2c_unlock_obj) }, { MP_ROM_QSTR(MP_QSTR_writeto), MP_ROM_PTR(&bitbangio_i2c_writeto_obj) }, { MP_ROM_QSTR(MP_QSTR_readfrom_into), MP_ROM_PTR(&bitbangio_i2c_readfrom_into_obj) }, }; STATIC MP_DEFINE_CONST_DICT(bitbangio_i2c_locals_dict, bitbangio_i2c_locals_dict_table); const mp_obj_type_t bitbangio_i2c_type = { { &mp_type_type }, .name = MP_QSTR_I2C, .make_new = bitbangio_i2c_make_new, .locals_dict = (mp_obj_dict_t*)&bitbangio_i2c_locals_dict, };